okay hi i'm gonna attempt to explain rng manipulation bc i find other guides not as helpful at actually explaining the mechanics
Everything here is formatted for Gen 4, mostly HGSS, for the moment, because that's the area I'm an expert in. I only know a bit about Gen 3, and basically nothing about Gen 5 atm, but i'll add stuff about that later, probably, hopefully
Essentially, my goal is to comb through all of the resources on the internet, and try to compile things in one place, noting what parts of guides are outdated and giving more explaination for the things that confused me when i started!
(Will this ultimately end up as MORE confusing? Who knows, maybe!)
Glossary
- RNG Manipulation = the act of exploiting a bunch of super precise timing to get cool shit instead of leaving it up to chance (you probably already know the actual defintion if you're here, especially considering i'm only sending this page to like 2 whole people rn)
- Seed = the rng that is set when you start up the game
- Delay = part of the timing that sets the seed
- Advances = list of what happens each time the rng moves forward.
- Pokefinder = program that you can put your information in and then search for the shiny you want, the most complicated step.
- Eon Timer = program for setting up the timer
- TID/SID = Trainer ID / Secret ID, that number on your trainer card, and the secret number the game assigns you. this is what ultimately determines what pokemon show up as shiny.
- PID = Pokemon ID, each pokemon has an ID assigned to them, whether a pokemon is shiny or not depends on this value along with your TID/SID combo.
- Retail = actual physical cartridges and hardware, not an emulator
Seeds
"A random seed (or seed state, or just seed) is a number (or vector) used to initialize a pseudorandom number generator." [wikipedia]
Basically, when you start up the game, one of these is set and it determines what pokemon you're going to be able to get. It looks something like this: CE12E04A [?]
Your seed is determined the moment you load your save file. This depends on the current time, and the delay between opening the game and loading the save file, together.
GEN 4: When you load into your save file during the RNG manipulation process, the first thing you're going to do is "verify your seed", via methods detailed below. This is essentially reading the RNG to make sure you hit the right timing, before moving on to the encounter.
Advances
Advances, also called "Frames" by people who want to confuse people [1], are each "step" of the RNG. These are dependant on the Seed you load into, and are set in place once you load the game.
"Advance" is sort of both a verb and a noun here. The RNG "advances" forward each time the game uses it, but "Advance" is also used to single out which step of the RNG you need to aim for. Pokefinder lists out each step of the RNG with an "Advances" value, this starts at 0, as the first step happens with 0 previous advances. It's easiest to point out which step you're aiming for by pointing at the value in the "Advances" column, so that's used as a noun as well. Does this make any sense?
GEN 4 NOTE: There are actually multiple RNG processes going at once. If you are playing HGSS, and using RNG manipulation for anything other than eggs, you can ignore this for now. If you are playing DPPt, or are trying to get eggs in HGSS, here's more info on the two types that matter for RNG manipulation.
Pokefinder
Pokefinder is a super complicated tool that is how you figure out how to get the pokemon you want! More details when I explain how to use it.
Eon Timer
Eon Timer is a less complicated tool to help you time loading into the game, so you can get the seed you're aiming for! oh shit, there's a web version now, actually by the person who made it, neat!
Delay
The timing between booting up the game and loading into your save file. This will be one of the values you find via Pokefinder and place into Eon Timer.
NOTE: For some reason, your game will only be able to hit either Even or Odd numbered delays. This is dependant on each game, so you will need to trial and error for a bit when you first start to figure out which ones you're hitting. (Supposedly, putting a Pokemon GBA game into the DS will flip your game from even to odd, or vice versa, but that didn't work when I tried it.)
Maybe explain this part later rather than here?: When you're trying to verify your seed, Pokefinder lists the neighboring seeds and their delays, with a way to figure out which one you hit instead if you didn't get the seed you were aiming for. This is important, so you know if you're close or if your timing is way off and you may need to correct something.
I chose that seed because it's the first one i got when searching to see if I could get a 0IV shiny lol.
There's the normal RNG and then there's the Egg RNG. Normal RNG controls everything you're normally going for, but Egg RNG is separate and determines what an Egg's PID will be when it's spawned into the daycare. (Note that IVs are not set on the Egg when it's spawned, meaning once it's ready to be picked up you can save the game + do another round of RNG to get the IVs you want. The IVs are set via the normal RNG that controls every other type of encounter.) This is also the main thing that's different between DPPt and HGSS, as the main way of verifying your seed in DPPt is via a poketch app that uses Egg RNG, not the normal one. I'll explain this more later.
Okay, some people call them frames because some games advance the RNG once per frame. In later pokemon gens, which I'm mostly talking about gen 4 here atm, the RNG only advances when it's used, which is why it's a lot easier to hit your target. You only have to time hitting the right seed, you can advance the RNG to exactly the right spot to get your target, and in most cases don't have to worry about randomness anymore. (most, because sometimes there's things like NPCs that will move and mess things up, for example.)